Apparatus for jet propulsion through water



F. ZWICKY APPARATUS FOR JET PROPULSION THROUGH WATER Filed Feb; 13, 1948 5 Sheets-Sheet 1 wi E;

123m JMD"- F. ZWICKY Mmh 14, 1961 APPARATUS FOR JET PROPULSION THROUGH WATER 3 Sheets-Sheet 2 Filed Feb. 13, 1948 F. ZWICKY March 14, 1961 APPARATUS FOR JET PROPULSION THROUGH WATER 3 Sheets-Sheet 3 Filed Feb. 13, 1948 INVENTOR. FRITZ ZW/CKY BY ATTORNEY United States Patent O APPARATUS FOR JET PROPULSION THROUGH WATER Fritz Zwicky, Pasadena, Calif., assignor, by mestre as signments, to Aerojet-General Corporation, Clncmnatl, Ohio, a corporation of Ohio Filed Feb. 13, 1948, Ser. No. 8,062 Claims. (Cl. 11S-1 3) This invention relates to jet propulsion and more particularly to jet propulsion of a device through a water medium. l

The principal object of this invention is to provide a jet driven device capable of operating through water at high speeds and great eiciency. A related object is to provide such a device which is capable of effectively utilizing the available energy of the propellant materials used.

Jet propulsion devices have heretofore been proposed for operation through water. Such devices usually comprise a duct having an opening at the front end through which water from the medium enters and an exhaust nozzle at the rear end through which the water passing through the duct leaves; and to create a reaction force a suitable propellant or fuel is injected into the device to create gases of reaction which build up pressure forcing the reaction products together with the water out the exhaust nozzle. e'

In my copending application Serial No. 550,693, liled August 23, 1944, entitled Reaction Motor, I have disclosed such a device for loperation through water, comprising a duct having a valve located back of the water inlet, with a combustion or reaction region back of the valve. The valve admits water from the inlet to the reaction region where propellant is introduced, and when the reaction occurs the pressure builds up, closing the valve and forcing the products in the combustion chainber out an exhaust nozzle.

In my copending applications Serial No. 559,951, filed October 23, 1944, issued as Patent No. 2,461,797 ou February 15, 1949, and Serial No. 570,843, tiled .lanuary 1, 1945, now abandoned, I have disclosed modified forms of such devices wherein the valve may be omitted. In these the pressure build up in the reaction region is limited by the head pressure at the inlet opening created as the device is propelled through its medium.

' In the operation of such devices, water reactive propellants have been used by introducing it into the reaction region, and when such reactive substances come into contact with the Water, the reaction spontaneously occurs, generating heat and gases which create the pressure to force the mass of gas and water out the exhaust nozzle to produce the propulsive force.

In the use of devices of the character noted above, the propellant is ordinarily placed under a pressure high enough to force it into the reaction region or chamber against the pressure already existing there. This has involved the use of pressurizing devices such as pressure tanks or means for applying the pressure on the propellant to force it to ow -against this pressure. Such pressure installations involve substantial weight and bulk.

In accordance with my present invention, I provide a jet propelled device for operation through water which can operate at very high pressures within the reaction region, thereby obtainingthe thermodynamic advantage of high pressure reaction. Furthermore it avoids the use of water inlet valves, and does not require use of -thrust of the unit.

2,974,625 Patented Mar.. 14, 1951 bulky or heavy pressurizing equipment for the propellant. Furthermore, I make use of the advantage of reacting water from the medium with water reactive propellant.

I carry out my invention by the provision of a reaction chamber having an exhaust nozzle and I provide a duct or conduit for leading water from the medium into the reaction chamber. I also provide means for introducing the propellant material intovthe chamber to react with the water. In order to force the water and the propellant into the reaction chamber against the high pressure due to the reaction there, I provide a turbine for operating a propellant pump and a water pump, the propellant pump serving to pump the propellant into the reaction chamber, and the water pump serving to pump water into the reaction chamber.

A feature is the provision of means for driving the turbine from pressure developed within the reaction chamber; the turbine thereby pumping water and propellant at a proper rate into the chamber. A related preferred feature is the provision of flow control means for the water and propellant to control the speed and ICC A feature which may be used is the provision of starting equipment which may conveniently be in the form of a small high pressure inert gas unit for pressurizing the flow of propellant into the reaction chamber to start it. l

A further feature of the invention is the provision of a water intake which may he fitted into a guiding iin of the nacelle of the jet propelled body.

The foregoing and other features of my invention will be better understood from the following detailed description and thev accompanying drawings, of which:

Fig. 1 is a broken schematic view showing a propulsion device according to my invention;

Fig. 2 is a rear view of an injector mount used in the arrangement of Fig. 1;

Fig. 3 is a cross-section Fig. 2;

Fig. 4 is a rear elevation view of the device shown in Fig. 1; and

Fig. 5 is a side elevation view, partly broken away and partly in cross-section, showing the reaction chamber, its exhaust nozzle and the injection arrangement used in the construction shown in Fig. 1.

Referring to Fig. 1, there isshown a mount or nacelle 10 which may be tubular in shape and adapted to be located or attached at the rear of a vessel or device to be propelled through water. IInasmuch as only the equipment located in the rear of this nacelle is pertinent to the present invention, the nacelle is shown broken away forward at its rear portion. Within the rear of the nacelle 10 is contained the jet propulsion apparatus and equipment to operate it in accordance with my invention. 'Ihis equipment comprises a reaction motor 11, a gas turbine 12, a water pump 13, and a fuel pump 14 operated from the turbine, a fuel or propellant storage tank 15, a compressed inert gas storage tank 16, and the related and connecting equipment correlating these operating elements of the device. All of this equipment is suitably fastened within the hollow or tubular part at the rear of the nacelle; and is constructed and operated as is more particularly described hereinbelow.

The reaction motor 11 comprises a reaction chamber 17, provided with a nozzle 18 having an orifice 19 preferably of the De Laval type. The downstream portion of nozzle 18, beyond the region of its throat, preferably dverges at a uniform angle; and the rear part of the nacelle is diminished in diameter so as to intersect with the expanding nozzle at the rear of the device'. AThe nozzle is permanently secured by suitable means such as welding, brazing, etc. This forms the exhaust opening view taken at line 3 3 of 49 ofthe motor assembly which is normally perpendicular to the longitudinal axis of the nacelle.

The forward end of therreaction chamber is closed by an injector head 20 (shown in Figs. 2, 3 and 5) for injecting water and propellant into the chamber. This comprises a disc-like member 21 having a number of annuli 22 cut or formed a substantial depth into the rear side of the disc (the upper side in Fig. 3), this arrangement being shown in Fig. 2 wherein the dotted circles represent the outer circumferences of the annuli. One of the annuli is centrally located coaxial with the central axis of the disc; and the other annuli (of which there are six in the arrangement shown in the drawing) are arranged in a circle equi-distant from the central annulus and equi-distant from each other. Each of the annuli arranged around the circle is connected to the adjacent annulus by a connecting channel 23; and the central annulus is connected to each of the outer annuli by a separate connecting channel 24, these connecting channels being in the form of grooves in the side of the disc 21.

The front side 25 of the injector head is provided with a number of frusto-conical depressions 26, these being the same in number as the number of the annuli on the other side of the plate. There is provided an individual frusto-conical depression 26 opposite each one of the annuli; and the ycentral axis of each depression is coaxial with the central axis of its related annulus. Each annulus is provided with a pair of oppositely positioned holes or bores 27 leading from the annulus to the side of a juxtaposed frusto-conical depression; and in each of these holes or bores 27 there is inserted, for example by threading, a replaceable injector nozzle 28. These nozzles 28 are for injecting into the chamber, water which is carried to the nozzles through the annular grooves and their connecting grooves or channels. For the purpose of carrying the water to the grooves and to the injectors 28, there is provided a conduit 34 leading into the side of the disc 21 and communicating with one of the annuli 22 which thereby brings the fluid from conduit 34 to all the annuli and to all the injector nozzles 28.

For the purpose of carrying propellant to the chamber there is provided an axial bore or hole 30 formed through the disc` 21 leading from the small end 29 of each frustoconical recess and brought through to the front of the disc; and there is fitted into each of the holes 30, an injector 35. Each of injectors 35 comprises a cylindrical body 36, reduced in diameter at one end to lit into the respective holes 30; and an axial bore 37 is provid-ed through each cylindrical body, extending into the related frusto-conical recess 26. The outer end of the bore is counter-bored and threaded at 38 and at its inner end it is threaded to receive an injector 39.

As some fuels that may be used to operate the motor may tend to congeal or solidify at the temperatures which may be encountered in operation, I provide means for keeping the temperature high enough to maintain it in a fluid condition. This means comprises a plurality of cylindrical bores 41 formed in the fuel injectors 35 and into which suitable heating elements such as electric resistance type heaters may be inserted. The position of injectors 28 relative to injectors 39 is such that the streams of fluid projected through injectors 28 intersect the streams from orifices 39.

Annular grooves 22 and connecting channels 23 and 24 are closed by a circular plate 31 which has a series of holes drilled to conform with holes 36 in injector head 20. Leakage from channels 22, 23 and 24 is prevented by a gasket 32 which is held tightly in between plate 31 and the cylindrical body portion of head 20 byl a plurality of bolts 33. Bolts 33 hold the injector head 20 securely in place on reaction chamber 17. A

For the purpose of simultaneous introduction of propellant fluid into each of the uid injectors 39 there is provided a manifold 42 (see Fig. 5) and preferably a heat shield 61 covers the manifold and injector bodies.

The gas turbine 12, located in the nacelle at a position ahead of `reaction chamber 17, contains a turbine wheel (not shown) provided with an elongated shaft.

Turbine 12 is driven by a portion of the gases under pressure generated within the reaction chamber 17; and these are conducted through a conduit 47 to the turbine nozzle through an outlet 46 located at a suitable point in the wall of the reaction chamber 17. After the gases have transferred their energy to the turbine wheel they are exhausted from the turbine through a series of conduits 48 which have their exhaust openings symmetrically positioned with respect to the axis of the nacelle and discharge into the surrounding Ymedium at a point near the exhaust opening 49 in the rear of the nacelle.

The details of construction of the turbine ,and its motor need not ber illustrated in greater detail as it may be a conventional ltype of turbine known -to the'art.

The speed at which turbine 12 operates is controlled by a gas flow regulator 50 located at the conduit from gas outlet 46 to the turbine; and this regulator may be set or adjusted to determine the rate of gas ow to the turbine.

The propellant fuel pump 14 and the water pump 13 are driven from the turbine shaft. Propellant from supply tank 15 is conducted to the intake of fuel pump 14 by a conduit 43 While water reaches the intake of pump 13 by means of a conduit 44 which leads in from outside the nacelle. A preferred arrangement of such a water conduit is shown in Figure 1 in which the water inlet is located in the leading edge of guiding vane 45. The discharge outlet 51 of fuel pump 14 is connected to a flexible coupling 52 which connects through a fluid ow control valve 53 to the `intake manifold of the injector head. The ow control valve regulates the rate at which the propellant will flow to and through the propellant injectors in the injector head. A sui-table ow control valve for the purpose is illustrated in the pamphlet entitled Automatic Flow Control Regulator, published by the Waterman Engineering Company of Evanston, Illinois. In said pamphlet the drawings A- 19069 and B-l9047 show suitable ow control regulators manufactured by that company.

The discharge outlet 54 of water pump 13 is connected through a flow control valve 55 to the water vconduit 34; and this flow control valve establishes the amount of water that will enter the reaction chamber through water injectors 28.

Since the operation of the pumps which feeds the water and propellant fuel into the reaction chamber is dependent upon the rotation of the gas turbine shaft it is obvious that no reactants can be pumped into the reaction chamber while the turbine is stationary. Accordingly, in order to start the operation without the operation of the pumps there is provided a small tank 16 containing a compressed gas which is preferably inert such as helium or argon; and the tank is provided with a reducing valve 56 to regulate the discharge pressure of the inert gas. A starting valve 57 is connected to reducing valve 56 and to storage tank 15 by a conduit 58, while a conduit 59 connects valve 56 to a pressure sensitive opening device 60 in flow control regulator 53. The gas under pressure will open this valve when the pressure in the storage tank 15 and in the pressure sensitive device is raised sufficiently.

The fuel which may be put in the tank 15 for use in operating the 'motor should be a suitable fuel reactive in the water. "In my copending application Serial No. 550,693 mentioned above, I have set forth fuels suitable for reaction with water. These are the alkali metal borohydrides, metal hydrides, metal silicides and borides and metals'which" combine violently with water giving o't' gas and heat. I prefer to` use-such substances as lithium borohydride' (LiBH4), aluminum borohydride lithium hydride (LiH), boron hydride (BZHB) or higher boron hydrides as propellants to generate the required power for propulsion, through water, although the operation is not limited to these substances. Other substances that may be used, for example, in place of the above are molten magnesium, molten lithium, molten aluminum, amalgamated aluminum, sodium hydride (NaH), sodium potassium alloy, calcium hydride (CaHz), beryllium borohydride (Be(BH4)2), magnesium borohydride (Mg(BH4)2), sodium borohydride (NaBH4), activated boron and activated silicon. Silicon and boron areactivated by alloying them with substances that make them water reactive. Since the materials are continually introduced while the reaction `is taking place and heat is being generated it is possible to employ materials that would normally react slowly at lower temperatures. When these materials are subjected to the heat developed by the reaction they will explode violently when contacting water. This broadens the eld of materials that may be utilized as propellants.

The way in which the apparatus operates is as follows: While the unit is at rest immersed in water, reaction chamber 17 will become partially filled with water that enters through the nozzle opening 49. The starting valve 57 is opened and compressed argon, helium or other inert gas at a pressure predetermined by the setting of valve 56` isV released into propellant storage tank 15 and againstthe pressure sensitive portion 60 of ow control valve 53. The pressure in tank 15 will force the propellant material through conduit 43, pump 14, expansion bellows 52 and flow control valve 53. When the pressure in tank 15 and conduit 59 have become sufficiently elevated to open the pressure sensitive mechanism 60 of the flow control valve, propellant will pass through flow control valve 53 into the manifold 42 and through the fuel injectors 39. The propellant will react with the Water which is standing in the reaction chamber, generating gas and heat. A portion of the gases thus created will escape through the bypass 46 and be conducted by the conduit 47 against the turbine Wheel (not shown) of turbine 12. "This will set the turbine in operation and will operate propellant and Water pumps 14 and 13 which in turn will supply propellant and water under pressure to their respective injector orifices 39 and 28. The water and propellant will be injected in thin streams against each other in the directions of the respective injector orifices shown in Fig. 3; resulting in spontaneous reaction upon the impingement of the two fluids in the chamber.

As soon as the pressure from the gases formed within the reaction chamber becomes high enough to operate the turbine at full speed the fuel and water pump will take over the task of.supplying propellants under pressure and the compressed inert gas from tank 16 will be shut 0E. The principal portion of the gases generated in the reaction chamber 17 are exhausted through the throat 19 of the nozzle 18 and escape into the surrounding medium through opening 49; and the reaction of the mass of gases creates the thrust necessary to force the nacelle with its interior assembly through the water at high speeds.

The exhaust gases leaving the turbine wheel are conducted toward the rear of the device by a pair of symmetrically positioned, conduits 48 which exhaust into the surrounding medium and contribute slightly to the total thrust. It is preferable, in order to prevent any deflection to one side or the other from the chosen course of travel, to have the turbine exhaust conduits symmetrically positioned with reference to the longitudinal axis of the nacelle.

An important advantage of this invention is the fact that reactions can be conducted at high chamber pressures, which permit the gases to do more work on eX- panding from the higher pressures, thus insuring a more substantial conversion of the thermodynamic energy of the reaction into useful work.

Another advantage of the device over the previouslyi known type motors is the elimination of complicated Valve mechanisms such as have been heretofore used to admit water to a reaction chamber. A further advantage is the avoidance of the necessity for a forward velocity to build up a pressure head, such as has been used in other types of motors'heretofore known.

A further advantage is that it may be operated over a wide range of speeds since the pressure at which the gases are generated within the reaction chamber may be greatly varied and is limited mainly by the strength of material utilized in making the reaction motor.

A further factor which may in many cases be advantageous is that in the operation of my novel' unit, great quantities of Water are not required to be sent through the unit; but instead, only the stoichiometric proportion of water for reaction with the amount of propellant injected into the chamber, is required to produce the operation; although greater amounts of water than the stoichiometric amounts will not be harmful. In previously known types of jet propulsion units for operation through water a relatively large volume of water has been sent through the inlet opening of the duct to be exhausted out the oulet opening. This involves problems of handling the water by valves or otherwise and also of obtaining proper reaction of the propellant injected into such a volume of Water. In my present construction however, the problem is greatly simplied by the rela tively small amount of water which can be readily mixed with the propellant for reaction. This permits the use of the water injectors and the propellant injectors in the injector head directed to impinge against each other to insure good and quick reaction.

I claim:

l. A jet propulsion unit for operation through water comprising a housing from which the water is excluded, there being located within said housing, a reaction charnber, an exhaust nozzle from the reaction chamber and exiting into the Water, a water injector and a fuel injector connected with the reaction chamber, each injector comprising an oritce for injecting streams of water and fuel separately into the chamber, a water inlet for taking Water from the medium through which the unit is traveling, a iirst conduit from the water inlet to the Water injector, a water pump connected with the rst conduit for pumping the water at elevated pressure through the water injector into the chamber, a iluid propellant tank, a second conduit from the tank to the fluid injector, a propellant pump connected with the second conduit for pressurizing the fuel to the fuel injector, a gas turbine, a gas conduit leading from said chamber to said turbine to drive the turbine, and coupling means for driving the pumps from the turbine, whereby the propellant and Water are injected simultaneously into the chamber for combustion and the gases of combustion exhaust through the nozzle to produce the propulsive thrust and part of the gases in the chamber drive the turbine.

2. A jet propulsion unit for operation through water comprising a housing from which the water is excluded, there being located within said housing, a reaction chamber, an exhaust nozzle from the reaction chamber and exiting into the water, a water injector and a fuel injector connected with the reaction chamber, each injector comprising anl orifice for injecting streams of water and fuel separately into the chamber, a water inlet for taking water from the medium through which the unit is traveling, a first conduit from the water inlet to the water injector, a water pump connected with the rst conduit for pumping the Water at elevated pressure 7 through the water injector into the chamber,`a ow control device included in the conduit for controlling the ow of water into the chamber, a iiuid propellant tank, a second conduit from the tank to the fluid injector, a

`propellant pump connected with the second conduit for pressurizing the fuel to the fuel injector, a gas turbine, a gas conduit leading from said chamber to said turbine to drive the turbine, and coupling means for driving the pumps from the turbine, whereby the propellant and water are injected simultaneously into the chamber for combustion and the gases of combustion exhaust through the nozzle to produce the propulsive thrust and part of the gases in the chamber drive the turbine.

3. A jet propulsion unit for operation through water comprising a housing from which the water is excluded, there being located within said housing, a reaction chamber, an exhaust nozzle from the reaction chamber and exiting into the water, a water injector and a fuel injector connected with the reaction chamber, each injector comprising an orice for injecting water and fuel separately into the chamber, a water inlet for taking water from the medium through which the unit is traveling, a rst conduit from the water inlet to the water injector, a water pump connected with the first conduit for pumping the water at elevated pressure through the water injector into the chamber, a flow control device connected with the first conduit for controlling the flow of water into the chamber, a iiuid propellant tank, a second conduit from the tank to the fluid injector, a propellant pump connected with the second conduit for pressurizing the fuel to the fuel injector, a liow control device connected with the second conduit for controlling the ow of fuel from the pump to the chamber, a gas turbine, a gas conduit leading from said chamber to said turbine to drive the turbine, and coupling means for driving the pumps from the turbine, whereby the propellant and water are injected simultaneously into the chamber for combustion and the gases of combustion exhaust through the nozzle to produce the propulsive thrust and part of the gases in the chamber drive the turbine.

4. Apparatus according to claim 3, in which there is provided in the housing an auxiliary container, inert gas received by the auxiliary container under pressure, and means for injecting said inert gas into said fuel tank to cause fuel to flow into the chamber even when the fuel pump is not pumping.

5. In a jet propulsion system for propelling water craft, the combination comprising a nacelle having within its interior a reaction chamber provided with an exhaust nozzle leading rearwardly from the chamber to the water, a propellant injector and a water injector leading into the chamber, a gas turbine having a shaft, a propellant pump and a water pump coupled to the shaft, a source of liquid propellant supply, a rst conduit means leading from a source of liquid propellant supply to the intake of the propellant pump, a second conduit means from the outlet of the pump to the propellant injector, said nacelle having a water inlet opening, a third conduit means from the nacelle water inlet opening to the water pump and a fourth conduit means from the outlet of the water pump to the water injector, and a gas conduit communicating from the chamber to the turbine for driving the turbine.

6. In a jet propulsion system for propelling water craft, the combination comprising `a nacelle provided on its exterior with guiding vanes adapted to lie in the water for guiding the craft, said vanes having leading edges, the nacelle having in its interior a reaction chamber with an exhaust nozzle leading rearwardly from the chamber to the water, a propellant injector and a water injector leading into the chamber, a gas chamber having a shaft, a propellant pump and a water pump coupled to the shaft, a source of liquid propellant supply, a first conduit means leading from a source of liquid propellant supply to the intake of the propellant pump, a second conduit means from the outlet of the propellant pump to the propellant injector, said nacelle guiding vane leading edge having a water inlet opening therein, a third conduit means from the water inlet opening to the water pump, a fourth conduit means from the outlet of the water pump to the water injector, and a gas conduit communicating from the chamber to the turbine for driving the turbine.

7. A combination according to claim 6 in which a tank of compressed inert gas is located within the nacelle, said inert gas tank having an outlet, pressure regulator located in said tank outlet to maintain substantially uniform pressure, a flow control regulator located in said second conduit means between the propellant pump and the propellant injector to limit the tlow of propellant into the propellant injector, valve means connected with the output from the pressure regulator, said valve means having an outlet, a fifth conduit means attached to the outlet of the valve means and the propellant tank to pressurize the propellant tank when the valve means is turned on, and a sixth conduit from the outlet of the valve means to the flow control regulator.

8. A jet propulsion unit for operation through water comprising: an elongated housing of circular cross-section, a nacelle attached at the rear of said housing, said nacelle being closed at the front to prevent water from flowing through it, a rocket motor within the nacelle, said motor having a combustion chamber and an exhaust nozzle leading rearward from the chamber and opening into the water, a first injection means attached to the chamber for injecting propellant into the chamber, a Second injection means at the chamber for injecting water into the chamber, a source of liquid propellant, a first pump attached in supplying relation to the said first injection means, a second pump attached in supplying re lation to the said second injection means, a pipe attached to said source of liquid propellant and to said first injection means, and a gas turbine connected to the pumps for driving said pumps, a gas conduit leading from the combustion chamber to the turbine to drive the turbine from the gases of combustion, water inlet means, and conduit means connecting the second inlet means with the second pump, said second inlet means being located at the side of the nacelle and having an opening facing toward the direction of motion of the unit.

9. A jet propulsion unit according to claim 8 in which the propellant injection means comprises a head attached to the chamber and includes an orice passing through the head and into the chamber, and a boss provided on the head outside the chamber, through which the oriice passes, said boss being provided with a recess in proximity to the orifice, in which a heating element may be inserted.

10. Apparatus according to claim 9 in which the injection orifice means passes through the head.

References Cited in the tile of this patent UNITED STATES PATENTS 515,500 Nobel Feb. 27, 1894 1,656,269 Dieter Jan. 17, 1928 2,024,274 Campini Dec. 17, 1935 2,351,750 Fawkes June 20, 1944 2,395,113 Goddard Feb. 19, 1946 2,463,820 Stafford et al. Mar. 8, 1949 FOREIGN PATENTS 500,683 France Jan. 2, 1920 625,104 France Apr. 19, 1927 

